If `f(x)=(a^x+a^(-x))/2` and `f(x+y)+f(x-y)=kf(x)f(y)` then `k=`

If f(x)=(a^(x))+a^(-x)/(2) and f(x+y) +f(x-y)=Kf(x) f(y) , then the value of K.

Given the function f(x)=(a^(x)+a^(-x))/(2)(a>0) If f(x+y)+f(x-y)=kf(x)*f(y) then k has the value equal to

Given the function f (x) =(a ^(x) + a ^(-x))/(2), a gt 2, then f (x+y) + f(x -y) =

If f(x)=(2^x+2^-x)/2 , then f(x+y) f(x-y) is equal to:

If f(x)=(2^(x)+2^(-x))/(2) , then f(x+y).f(x-y) is equal to

If f(x) =((x-a)(x-b))/x and (f(x))/((x-y)(x-z))+ (f(y))/((x-z)(y-z)) + (f(z))/((z-x)(z-y)) = K/(xyz) , then K=

Given the function f(x)=(a^(x)+a^(-x))/(2)(wherea>2)dot Then f(x+y)+f(x-y)= (A) 2f(x).f(y) (B) f(x).f(y) (C) (f(x))/(f(y)) (D) none of these

Given the function f(x)=(a^(x)+a^(-x))/(2) ( where a gt 2 ). Then f(x+y)+f(x-y)=